JP2011038916A - Detector, display apparatus, and method for measuring proximal distance of object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately and optically detect a distance to a specimen, and inhibit an increase in a cost. <P>SOLUTION: A detector has an optical sensor array 3 having an optical anisotropy, a detection/drive section 6 of the optical sensor array, and a height detection section 7. The detection/drive section 6 drives the optical sensor array 3, images the specimen, and generates a plurality of different detection images P1, P2 based on the light reception anisotropy. The height detection section 7 detects the distance (a height) from a sensor light reception plane of the optical sensor array 3 to the specimen by using a plurality of the detection images. At this time, the height detection section 7 detects the height based on the magnitude of a displacement generated by a light reception anisotropy difference in image portions corresponding to shadows or reflections of the specimen included in a plurality of the detection images. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a detection device that detects a distance (height) from a light receiving surface of an optical sensor that images a detection object to the detection object when the detection object such as a hand or a stylus pen comes close to the detection object, The present invention relates to a display device having a height detection function. The present invention also relates to a method for measuring the proximity distance of an object using the light receiving anisotropy of an optical sensor array.

A detection device that detects contact or proximity of an object to be detected such as a person or a stylus pen is known. There is also known a display device having a contact sensor function in which an optical sensor is arranged on the display device to detect that an object to be detected contacts or approaches the display surface.
Examples of the contact detection method include an optical method, a capacitance method, and a resistance film method. Of these, the optical type and the capacitance type can detect not only contact but also proximity.

By the way, a new user interface (UI) has been developed as a substitute for buttons for operating devices by directly touching the display screen of the display device. In particular, in mobile devices such as mobile phones, development of UI using a display screen has been activated.
On a relatively small display screen such as a mobile device, when operating with a finger, an icon of a certain size is required from the viewpoint of operability. However, if the icons are enlarged with emphasis on operability, the amount of information that can be listed decreases.

In order to deal with such inconvenience, a finger or the like is detected at a non-contact stage (proximity stage), and a display state of an image or the like displayed on the display panel is changed according to the movement of the finger or the like. An unprecedented information display method has also been proposed (see Patent Document 1).
The method of contact and proximity detection of the display device described in Patent Document 1 is an electrostatic capacitance type, and is configured so that the display state can be changed according to the proximity distance of a finger or the like. Only a rough proximity distance can be detected for this purpose. That is, in proximity detection of this display device, a change in capacitance is converted into a change in frequency, and the change in frequency is converted into a voltage. When the voltage is high, it is determined that the finger causing the change in capacitance is close, and when the voltage is low, it is determined that the finger is far away.

JP 2008-117371 A

If the capacitance type capacitance change is small, it will be buried in the noise level. In particular, when a display or a proximity detection function is built in the display device, a wiring whose potential changes for display is arranged near the detection electrode, and the potential change of the wiring is easily induced noise and superimposed on the detection electrode. Even if the display device is not of a built-in type, the detection of the distance to the object to be detected by the capacitance type is generally not possible because the detection signal is based on the change in capacitance.
In order to enable detection even with a small change in capacitance, in Patent Document 1, it is necessary to prepare a capacitance detector using an oscillator. For this reason, the display device (or detection device) described in Patent Document 1 has a disadvantage that the cost becomes high.

  The present invention provides a detection device and a display device that can optically detect (or measure) a distance from an object to be detected with high accuracy while suppressing an increase in cost. The present invention also provides an object proximity distance measuring method that enables highly accurate detection at low cost.

The detection apparatus according to the present invention includes an optical sensor array having optical anisotropy, a detection drive unit for the optical sensor array, and a height detection unit.
The detection driving unit drives the optical sensor array to image a detection object, and generates a plurality of different detection images based on the light reception anisotropy.
The height detection unit inputs the plurality of detection images, and detects a distance (height) from the sensor light receiving surface of the photosensor array to the detected object using the input plurality of detection images. In more detail, the height detection unit is based on the magnitude of the positional deviation caused by the difference in the light reception anisotropy in the image portion corresponding to the shadow or reflection of the detected object included in the plurality of detection images. To detect the height.

The optical sensor array itself may have light reception anisotropy, or for example, the light sensor array may be provided with light reception anisotropy by a light reception anisotropy application unit. In the former case, for example, a ridge that partially blocks light from one side and does not block much light from the other side with respect to the light receiving surface of the photosensor array may be integrally formed by a semiconductor process.
On the other hand, the detection device in the latter case may include a wavelength selection filter unit for wavelength selection such as a color filter, a light shielding filter, or a lens array as a light receiving anisotropy imparting unit.

In particular, when a wavelength selection filter or the like is provided as the light-receiving anisotropy imparting unit, the detection driving unit may generate the plurality of detection images by imaging a plurality of times with light in different wavelength ranges.
In this case, the photosensor array is provided with the light-receiving anisotropy due to the wavelength dependence of the amount of light incident from different directions when receiving the transmitted light of the light-receiving anisotropy providing unit. A plurality of optical sensors are two-dimensionally arranged. The said detection drive part irradiates the said to-be-detected object with the some light which each has a mutually different wavelength range by time division. In addition, the detection driving unit may determine the time of each light received when the reflected light reflected and returned by the object to be detected is received by the plurality of optical sensors after passing through the light receiving anisotropy imparting unit. Control in time division in synchronization with irradiation. By this time-division control, imaging is performed a plurality of times, whereby a plurality of detected images are generated, and the height is detected based on the deviation of the images.

  The display device according to the present invention includes a photosensor array, a detection drive unit, and a height detection unit, similarly to the above-described detection device. In addition, the display device includes a light modulation unit and a display surface. The light modulation unit modulates incident light in accordance with an input video signal and displays the generated display image from the display surface.

An object proximity distance measuring method according to the present invention includes the following steps.
(1) A step of driving a photosensor array having light reception anisotropy to image an object to be detected and generating a plurality of different detection images based on the light reception anisotropy.
(2) The sensor of the optical sensor array based on the size of the positional deviation caused by the difference in the light receiving anisotropy in the image portion corresponding to the shadow or reflection of the detected object included in the plurality of detection images. Measuring a distance (height) from a light receiving surface to the object to be detected;

Another object proximity distance measuring method according to the present invention includes the following steps.
(1) A step of imaging an object to be detected a plurality of times with a combination of optical sensors corresponding to different light receiving anisotropies from a plurality of optical sensors in the optical sensor array having light receiving anisotropy.
(2) Based on the size of the positional deviation caused by the difference in the light receiving anisotropy in the image portion corresponding to the shadow or reflection of the detected object included in the plurality of detection images obtained by the plurality of times of imaging. Measuring the distance (height) from the sensor light receiving surface of the optical sensor array to the detected object.

In the present invention, an optical sensor array is provided in the same manner as a normal optical contact sensor, but height detection is possible because this has light receiving anisotropy. Therefore, the cost is low, and since the shift between images is used, the accuracy is higher than that of the capacitance type.
As described above, according to the present invention, it is possible to provide a detection device and a display device that can accurately detect (or measure) the distance from an object to be detected while suppressing an increase in cost. Further, according to the present invention, it is possible to provide a method for measuring the proximity distance of an object that enables highly accurate detection at a low cost.

It is a figure which shows the principal part of the detection apparatus in connection with 1st Embodiment. It is explanatory drawing of the area division in the light-receiving surface of a detection apparatus. It is explanatory drawing which shows the example of a combination of the optical sensor from which the anisotropy provision direction differs in each area | region of FIG. It is a figure which shows the 1st method of height detection. It is a figure for demonstrating the improvement of the 1st method of height detection. It is a figure which shows the 2nd method of height detection. It is a block diagram showing the whole structure of the display apparatus in connection with 2nd-5th embodiment. It is a figure which shows the structural example of an I / O display panel. It is an equivalent circuit diagram of the display pixel part and sensor part which are contained in a pixel unit. It is a figure which shows the connection relation of three pixels for 3 primary color displays, and a sensor read-out H driver. It is the top view and sectional drawing of the pixel unit of the display apparatus in connection with 2nd Embodiment. It is an arrangement top view of a display field and a sensor field of a display concerning a 2nd embodiment. It is a perspective view which shows the path | route of light when a fingertip is made to adjoin to the display surface of the structure shown in FIG. It is a timing chart which shows the blinking period of a backlight. 9 is a timing chart showing light emission, imaging, and data writing scans in the second embodiment. It is a figure which shows the analysis result of imaging data in 2nd Embodiment. It is a graph which shows the relationship between finger height and the distance between peaks of a detection image. It is a figure in connection with the modification of 2nd Embodiment. It is the top view and sectional drawing of the pixel unit of the display apparatus in connection with 3rd Embodiment. It is an arrangement top view of a display field and a sensor field of a display concerning a 3rd embodiment. FIG. 20 is a perspective view illustrating a light path when a fingertip is brought close to the display surface having the configuration illustrated in FIG. 19. It is a graph which shows the transmission spectrum of RB filter and RGB filter. It is a graph which shows the wavelength range of RGB light. It is a figure which shows the analysis result of imaging data in 3rd Embodiment. It is a figure in connection with the modification of 3rd Embodiment. It is a figure which shows the relationship between the lens and sensor arrangement | positioning of a display apparatus in connection with 4th Embodiment. It is sectional drawing and a top view of the display apparatus in connection with 5th Embodiment. It is a perspective view of the television in connection with 6th Embodiment. It is a perspective view of the digital camera in connection with 6th Embodiment. It is a perspective view of the notebook type personal computer in connection with 6th Embodiment. It is a perspective view of the video camera in connection with 6th Embodiment. It is an opening / closing view, a plan view, a side view, a top view, and a bottom view of a mobile phone according to a sixth embodiment.

Embodiments of the present invention will be described with reference to the drawings mainly using a liquid crystal display device as an example of a display device.
Hereinafter, description will be given in the following order.
1. First Embodiment: Outline of an embodiment for carrying out the invention (example of a detection device).
2. Second Embodiment: Application of the present invention to a field-sequential liquid crystal display device that irradiates light for each color in a time-sharing manner and performs imaging in a time-sharing manner.
3. Third Embodiment: A space division type liquid crystal display device using a light shielding filter to which the present invention is applied.
4). Fourth Embodiment: Application of the present invention to an organic EL display device.
5). Fifth embodiment: a display device example having a light receiving anisotropy using a lens array.
6). Fifth Embodiment: Application example of the present invention to an electronic device.

<1. First Embodiment>
[Configuration of detection device]
1A and 1B show a main part of a detection apparatus according to an embodiment of the present invention.
The detection device 1 illustrated in FIG. 1A includes at least a substrate 2, a photosensor array 3, a light receiving anisotropy imparting unit 4, and a protective layer 5. The outermost surface of the protective layer 5 is a detection surface 5A on which an object to be detected (such as a finger or a stylus pen) approaches.

  Here, in the optical sensor array 3, as shown in FIG. 1B, optical sensors PS are arranged in a matrix. The optical sensor PS includes a photodetector formed on a substrate using a semiconductor process and a sensor circuit for controlling the photodetector. Details of an equivalent circuit of the optical sensor PS will be described in an embodiment described later.

  The substrate 2 may be a semiconductor substrate. In that case, a photodetector and a sensor circuit constituting the optical sensor PS are directly formed on the substrate 2 using a semiconductor process. The substrate 2 may be a substrate made of an insulator. In that case, a thin film semiconductor layer is formed on the insulating substrate using a TFT (thin film transistor) formation process, and a photodetector and a sensor circuit are formed on the thin film semiconductor layer. Furthermore, a form in which an insulating layer is formed on a semiconductor substrate and a thin film semiconductor layer is formed thereon can also be employed.

In any case, interconnection lines for photosensors are formed in a row (horizontal) direction and a column (vertical) direction by a multilayer wiring structure with respect to the array of photosensors.
The detection device of the illustrated example has N scanning lines SCN that connect the optical sensors PS in the horizontal direction and separate in the vertical direction as interconnection wirings, and M that interconnect the optical sensors PS in the vertical direction and separate in the horizontal direction. It has two sensor lines SL.

The optical sensor array 3 thus formed has its own light receiving anisotropy, and the light receiving anisotropy imparting portion 4 is disposed on the light receiving surface side of the optical sensor array 3 as shown in the example of the drawing. In some cases, the photosensor array 3 is provided with light receiving anisotropy.
Here, “light reception anisotropy” refers to a property at the time of light reception in which the light reception sensitivity is different for light entering the optical sensor PS in different directions (light from the detected object side). That is, the property that the sensor output is high for light incident at a certain angle and the sensor output is low for light incident at another angle is called light receiving anisotropy.

  As a case where the optical sensor array 3 itself has light receiving anisotropy, the light receiving anisotropy may be given by the semiconductor physical property of the photodetector of the optical sensor PS. If this is not possible, a saddle-shaped part for light shielding on one side is formed on the light receiving surface side of the optical sensor PS by a semiconductor process or the like. With respect to the optical sensor array 3, the optical sensor array 3 itself may have light receiving anisotropy by weakening the light shielding property. In that case, the light-receiving anisotropy imparting unit 4 in FIG.

As the light-receiving anisotropy imparting section 4, a light-shielding filter that gives the optical sensor array 3 the same effect as the bowl-shaped part or a color filter that gives wavelength selectivity to light at different angles may be used. . Detailed forms and operations of the light shielding filter and the color filter will be described in embodiments of the display device described later.
Further, as will be described later in the present embodiment, a lens array in which lenses that divide the direction of light from an object to be detected into two directions are arranged in an array can be used as the light-receiving anisotropy imparting unit 4. . As such a lens, there is a semi-cylindrical cylindrical lens.

  As shown in FIG. 1B, a vertical drive circuit (V.DRV) 6V is connected to N scanning lines SCN, and a horizontal drive circuit (H.DRV) 6H is connected to M sensor lines SL. Yes. Further, a height detection unit (H.DET) 7 is connected to the sensor readout H driver 6SRH.

The sensor read V driver 6SRV and the sensor read H driver 6SRH constitute the detection drive unit 6. The detection drive unit 6 is a circuit that drives the optical sensor array 3 to pick up an image of an object to be detected and generates a plurality of different detection images based on the light reception anisotropy. The detection drive unit 6 may conceptually include a control circuit such as a CPU.
Each of the plurality of detected images is a set of sensor outputs from the optical sensor PS, and may be an analog image or a digital image. Each of the plurality of detection images is generated by converting sensor outputs discharged in parallel from the M sensor lines SL into digital signals as necessary in the sensor readout H driver 6SRH and storing them. This is image data given to the unit 7.

The height detection unit 7 may conceptually include a control circuit such as a CPU (not shown). The height detector 7 detects the distance (height) from the sensor light-receiving surface of the optical sensor array 3 to the object to be detected from a plurality of detection images under the control of a built-in or external control circuit. Circuit.
In some cases, the height detection unit 7 itself is a CPU, and in this case, the above functions of the height detection unit 7 are realized as a procedure of a program executed by the CPU. Further, the height detection unit 7 may include an image memory for processing as necessary.

  The detection apparatus 1 may be a shadow detection type detection apparatus that uses light for detection as external light, or may be a reflection detection type detection apparatus that reflects light emitted by the detection apparatus 1 by an object to be detected.

  In the case of the shadow detection type, external light is taken in from the detection surface 5 </ b> A, and the intensity distribution of the external light is sensed by the optical sensor array 3. When there is an object to be detected that is in contact with or close to the detection surface 5A, the intensity distribution of the external light incident on the optical sensor array 3 includes a dark image portion corresponding to the object to be detected. The height detection unit 7 obtains the magnitude of the positional deviation of the dark image portion corresponding to the shadow of the object from a plurality of detection images captured with different light receiving anisotropies, and calculates the height from the magnitude of the positional deviation. To detect.

In the case of the reflection detection type, it is necessary to add a light irradiation unit to the configuration of FIG.
The light irradiation unit is disposed, for example, on the back side of the substrate 2 opposite to the photosensor array 3. Although the light source of a light irradiation part is arbitrary, in order to reduce power consumption and size reduction, for example, it is configured to include at least one LED light source and a light guide plate that converts LED light into planar light. A reflection sheet is provided on the back surface of the light guide plate to increase the illuminance to the optical sensor array 3.

In the reflection detection, the planar light from the light irradiation unit generated in this way passes through the substrate 2 made of a transparent material such as glass, and further, the optical sensor array 3, the light receiving anisotropy imparting unit 4, and the protective layer. 5 is transmitted to the outside from the detection surface 5A. The emitted light (detection light) is reflected by the object to be detected, and the reflected light is returned from the detection surface 5A to the inside of the detection apparatus 1.
When the reflected light passes through the light receiving anisotropy imparting unit 4, the reflected light has a light receiving angle dependency for imparting the light receiving anisotropy and is incident on the optical sensor array 3.

  Each photosensor PS in the photosensor array 3 generates a plurality of at least two different detection images based on the light reception anisotropy. The principle by which the photosensor array 3 generates a plurality of different detection images depends on the configuration of the light receiving anisotropy imparting unit 4.

Although details will be described later, there is a case where the light receiving anisotropy imparting unit 4 is a light shielding filter that gives anisotropy to light incident obliquely from one side in one direction and light incident obliquely from the other side. In this case, the pattern of the light shielding filter corresponding to each photosensor PS is determined so as to selectively guide the two different lights to the photosensor array 3.
As an example, for every other first photosensor in the horizontal and vertical directions, light from the right is transmitted in the horizontal direction and light from the left is substantially blocked. On the other hand, the light from the left is transmitted in the horizontal direction and the light from the right is substantially shielded with respect to every other second photosensor remaining in the horizontal and vertical directions.
In this example, the first detection image is obtained from the discrete first photosensor group in the photosensor array 3, and the second detection image is obtained from the other discrete second photosensor group.

The oblique light component of the reflected light has a small incident angle (near vertical) when the object to be detected is close. On the other hand, the angle of incidence of this oblique light component increases as the object to be detected moves away from the detection surface 5A. For this reason, in the first and second detection images obtained by imaging the detected object that is the same subject, the shift of the image portion corresponding to the subject (detected object) becomes larger as the subject is farther away. There is a tendency to shift.
Utilizing this fact, the height detector 7 can accurately detect the height (the distance from the sensor light receiving surface to the detected object) from the magnitude of the shift of the image portion of the detected object.

  A method of providing anisotropy spatially as represented by a light shielding filter is hereinafter referred to as a space division method.

Even when the light receiving anisotropy imparting unit 4 is a color filter, the height detection principle itself is the same as the above case. However, in the case of a color filter, the method of giving anisotropy is different from the case of the light shielding filter.
The color filter serving as the light receiving anisotropy imparting unit 4 will be described in detail later. The color filter having different light transmission characteristics on both sides of the light shielding unit and the direction in which the anisotropy is desired is provided in the portion corresponding to the optical sensor PS. Part.
In this case, the detection device 1 is limited to the reflection detection type, and the light emitting unit needs to be configured to independently emit at least two colors of different colors. When a plurality of (for example, two) lights are received by one optical sensor PS, the light emission is performed in a time-sharing manner, and the light-receiving time of the optical sensor PS is also controlled in a time-sharing manner synchronized with the light emission. Do. Thereby, imaging with light of different colors is executed a plurality of times (for example, twice), and different detection images are obtained from each imaging.

  A method for allowing the anisotropy to be controlled temporally as represented by the color filter in this case is hereinafter referred to as a time division method.

On the other hand, a plurality of types of photosensors PS having different light receiving sensitivity center wavelengths corresponding to a plurality of colors are arranged close to each other, and the set of the plurality of types of photosensors PS is arranged in a matrix to form a photosensor. An array 3 can also be formed. In this case, even in a single imaging operation, by outputting a detection image for each type of photosensor PS (difference in light reception sensitivity characteristics), a plurality of positions in which the position of the image portion corresponding to the object to be detected is shifted according to the height. An image can be obtained.
However, in correspondence with the filter portion of the color filter, the closer the detected object is to a light component of a certain color, the greater the amount of light received by the photosensor that receives that color. For this reason, it is necessary to determine a plurality of types of photosensor arrangements so that the farther the object to be detected is for the light components of other colors, the greater the amount of light received by the photosensor that receives that color.

In this case, it is one of the space division methods in the sense that anisotropy is provided by a plurality of types of optical sensors PS. That is, when a color filter is used as the light receiving anisotropy imparting unit 4, a space division method can be employed in addition to the time division method.
Hereinafter, this method is referred to as a space division method using a combination of a color filter and an optical sensor characteristic in a sense that is different from a space division method using a light shielding filter.

  FIG. 2 shows the region division of the detection surface 5A of the detection apparatus 1 (detection panel) divided from the viewpoint of the anisotropic orientation in the light reception anisotropy imparting unit 4 (light shielding filter or color filter). FIG. 2 shows the entire detection surface of the detection panel divided into nine in-plane regions. FIG. 2 shows the detectable region in the z direction of the object to be detected when the direction away from the detection surface 5A is the z direction on the upper side and the left side of the 3 × 3 rectangular region (the inside of the triangle is Detectable area).

FIG. 3 shows an example of a specific combination of sensors used for height detection in each 3 × 3 rectangular area. In this example, for example, as shown in FIG. 3B, four units having anisotropy imparting directions in four directions from the relative positional relationship between the light shielding filter (light shielding portion) and the optical sensor PS are defined as one unit. To do. It is assumed that this unit is repeatedly arranged in the row direction and the column direction within the surface of the detection device (detection panel). Those having a different relative positional relationship between the light shielding portion and the optical sensor PS are denoted by reference numerals “4D, 4L, 4R, 4U”. Each of the three sides is surrounded by the light-shielding portion of the optical sensor PS, but light-receiving anisotropy is given to the remaining one direction not surrounded by the light-shielding portion. Hereinafter, the lower anisotropy imparting unit 4D, the left anisotropy imparting unit 4L, the right anisotropy imparting unit 4R, and the upper anisotropy imparting unit 4U are used as names indicating the orientation of anisotropy.
Here, an example is shown in which the light receiving anisotropy is imparted due to the relationship between the light shielding portion and the optical sensor PS. However, in the case of a color filter, a specific color component is blocked or attenuated in three directions as with the light shielding portion. Thus, the light receiving anisotropy can be imparted to the remaining one.

  In the central square region indicated by reference numeral “1C” in FIG. 3, a sufficient amount of light can be obtained from any direction, so any two or more of the combinations of the four light-shielding portions and the optical sensor PS can be used. May be combined.

  On the other hand, the right and left regions indicated by reference numerals “1R” and “1L” in FIG. 3 are, for example, the lower anisotropy imparting portion 4D and the upper anisotropy imparted to the lower and upper sides surrounded by circles. The anisotropy imparting unit 4U may be used to detect the position in the height x direction from the two images obtained respectively. This is because, in these left and right regions, the incident light amounts from the left and right are not equal, but the incident light amounts from the upper and lower sides are almost equal, and therefore it is desirable to use the upper and lower anisotropy.

  Further, the upper and lower regions indicated by reference numerals “1U” and “1D” in FIG. 3 are, for example, left anisotropy imparting portions 4L that are provided with anisotropy on the right and left sides surrounded by circles. The right anisotropy imparting unit 4R may be used to detect the position in the height z direction from the two images obtained respectively. This is because, in these upper and lower regions, the amount of incident light from the upper and lower sides is not uniform, but the amount of incident light from the left and right is substantially equal, so it is desirable to use the left and right anisotropy.

On the other hand, the four corner portions shown in FIG. 3 have different combinations of anisotropy imparting portions that are preferably used depending on their positions.
In the upper left corner area indicated by reference numeral “1CN_1”, the amount of incident light from above and from the left is limited, so the lower anisotropy imparting section 4D and the right anisotropy imparting section 4R may be used. For the same reason, the lower anisotropy imparting portion 4D and the right anisotropy imparting portion 4R are used in the upper right corner portion indicated by the reference numeral “1CN_2”. Further, the right anisotropy imparting unit 4R and the upper anisotropy imparting unit 4U are used in the area of the lower left corner portion denoted by reference numeral “1CN — 3”. Further, the left anisotropy imparting portion 4L and the upper anisotropy imparting portion 4U are used in the area of the lower right corner portion indicated by reference numeral “1CN — 4”.

  Thus, by selecting an appropriate combination of anisotropy units according to the position of the detection surface 5A, position detection in the height z direction can be performed from two images obtained from each. That is, when the anisotropy imparting unit is selected so as to be surrounded by a circle in FIG. 3, image misalignment occurs in the x direction or the y direction in the two images obtained from each. The height detection unit 7 in FIG. 1 performs position detection of the height (z direction) of the detection object based on the magnitude of this positional deviation.

Note that when the “light-shielding portion” shown in FIG. 3 is replaced by light shielding or transmission of a specific color by a color filter, it is possible to acquire an image by combining time division and space division.
In the case of a color filter, any two of right anisotropy imparting portion 4R, left anisotropy imparting portion 4L, lower anisotropy imparting portion 4D, and upper anisotropy imparting portion 4U (appropriate depending on the region of FIG. 3) Two color filter sections that select different wavelength ranges, that is, have color selectivity, are arranged on the two circles.

[Height detection method]
Next, two examples of height detection techniques performed by the height detection unit 7 using two detection images will be described. In the following description, the combination of the right anisotropy imparting unit 4R and the left anisotropy imparting unit 4L is taken as an example. However, as described above, the lower anisotropy imparting unit 4D and the upper anisotropy imparting unit 4D A combination with the anisotropy imparting unit 4U may be used. Further, depending on the location, such as a corner portion, the anisotropy imparting portion can be arbitrarily combined with one of the upper and lower sides and one of the left and right sides.
In the first method, two detection images output from the detection drive unit 6 in FIG. 1B are used, and based on the peak position of the sensor output distribution of the image portion corresponding to the detected object included in each of the detection images. Perform height detection.

FIG. 4 (A2) and FIG. 4 (B2) are explanatory diagrams of the first method.
4 (A2) and 4 (B2), the horizontal axis indicates the position in the direction of imparting anisotropy (for example, the x direction), and the sensor output (the amount of received light) that generates the image portion corresponding to the object to be detected. ) Indicates that the distance from the horizontal axis in the vertical direction increases. That is, the vertical axis represents the line profile of the detected image. FIGS. 4A1 and 4B1 respectively show the reference surface (for example, the detection surface 5A or the light receiving surface) of the detection object SD when the line profiles of the detection images of FIGS. 4A2 and 4B2 are obtained, respectively. The difference in distance from the surface is schematically shown.

  As shown in FIG. 4 (B1) and FIG. 4 (B2), the line profile of the first detection image is received from the right anisotropy sensor that has received the light transmitted through the right anisotropy imparting unit 4R (see FIG. 2). (Hereinafter, the first detection image P1) is obtained, and the x-direction address of the peak is relatively small. On the other hand, a second detected image line profile (hereinafter referred to as a second detected image P2) is obtained from the left anisotropy sensor that has received light transmitted through the left anisotropy imparting unit 4L (see FIG. 2). The peak x-direction address is relatively large. The x-coordinate difference between the peaks of the first and second detection images changes according to the size of the position of the detection object SD from the reference plane.

  When the detection object SD is relatively small, the peak of each output distribution is uniquely determined, so that the peak coordinate x1 of the first detection image P1 and the peak coordinate x2 of the second detection image P2 can be determined. The height detection unit 7 calculates the difference (x2−x1) between the peak coordinates, and obtains the height of the detection object SD from the size.

FIG. 5 shows the difference in the detected image profile depending on the size of the detection object SD.
FIG. 5B shows a case where the detected object SD is large as compared to a case where the detected object SD is small as shown in FIG.
The first method described with reference to FIG. 4 works well for a small object such as a fingertip. However, for a large object, the distance from the sensor light receiving surface to the object is accurate with the peak detection method. (Height) cannot be determined. This is because, in the case of a large object (detected object SD), each line profile of the first detection image P1 and the second detection image P2 may be flat near the peak, and detection is performed depending on the accuracy of peak detection in that case. This is because a large width occurs in the peak. For this reason, the positional deviation amount includes an error depending on which point of the detected peak width is subjected to the difference calculation, and as a result, the accuracy of height detection may be poor.

FIG. 6A and FIG. 6B show the second method.
The second method is a method that does not have the disadvantages of the first method. FIG. 6A illustrates an example of sensor output distribution when the detected object is small, and FIG. 6B illustrates the case where the detected object is large. An example of sensor output distribution is shown below.
In the second method, each detection image data is binarized using a certain threshold TH common to the first detection image P1 and the second detection image P2, and height detection is performed based on the binarized information. This binarized information is indicated by two circles in FIG. The first identification image PI1 obtained by converting the first detection image P1 and the second identification image PI2 obtained by converting the second detection image P2 are respectively detected image portions corresponding to the detected object. Equivalent to. Therefore, the size of the identification image is larger in FIG. 6B than in FIG. The size (diameter) of the identification image depends on how the threshold value TH is set, but the size itself does not affect the height detection.

  In height detection, the center of gravity position in the x direction is obtained for each of the first identification image PI1 and the second identification image PI2 obtained by the height detection unit 7. For example, a method of averaging addresses at both ends in the x direction can be adopted as a method of obtaining the center of gravity position.

  The two barycentric positions obtained in this way are constant regardless of their sizes as long as the position of the detected object with respect to the detection surface 5A is the same. Specifically, the barycentric position of the first identification image PI1 obtained in FIG. 6A matches the barycentric position of the second identification image PI2 obtained in FIG. 6B on the x axis. Further, the position of the center of gravity does not change even when the threshold value TH changes (in the case of a symmetric distribution). On the other hand, there may be a non-target distribution such as when the finger is tilted and close, but if the threshold value TH is the same, there is no significant difference in the center of gravity position.

In the second method, when the object to be detected is far away, the distribution peak decreases, which may be lower than the threshold value TH. In that case, the second method has a disadvantage that the threshold value TH must be changed.
Therefore, for example, the first method is used when the distribution peak is small or small detection object is detected, and the second method is used when the distribution peak is large or large detection object is detected. It can also be used together.

  Since the detection apparatus 1 according to the present embodiment that enables the above height detection is optical detection and height detection by image processing calculation, the difference calculation is performed even if noise is superimposed on the sensor output. Sometimes canceled. Therefore, the height can be detected with high accuracy. In addition, although the light receiving anisotropy imparting unit 4 may be required, a large circuit for performing sensor output conversion using an oscillator or the like is unnecessary, which is advantageous in terms of cost.

  In the second method, the size of the detected object can be detected using the binarized information as it is. In addition, when it is desired to detect the size of the object to be detected, it is necessary to detect the size in the first anisotropy applying direction and the size detection in the second anisotropy applying direction shown in FIG. Become.

<2. Second Embodiment>
The display device according to the second embodiment may be realized as a display panel (I / O display panel) capable of interactively inputting and outputting information with a user. Alternatively, a display module in which an I / O display panel and its external IC are mounted in a module, and further including an application program execution unit, such as a television receiver, a monitor device, etc. May be realized.
Hereinafter, the details of the second embodiment will be described by taking a display device including an execution unit of an application program as an example.

[Overall configuration of display device]
FIG. 7 is a block diagram illustrating the overall configuration of the display device.
The display device 10 illustrated in FIG. 7 includes an I / O display panel 10P, a backlight 20, a display drive circuit 1100, a light receiving drive circuit 1200, an image processing unit 1300, and an application program execution unit 1400.

  The I / O display panel 10P is composed of a liquid crystal panel (LCD (Liquid Crystal Display)) in which a plurality of pixels are arranged in a matrix over the entire surface, and a predetermined figure or character based on display data while performing line sequential operation. And the like (display function). Further, as described later, the I / O display panel 10P has a function (imaging function) of imaging an object that is in contact with or close to the display surface 11 of the I / O display panel 10P.

  The backlight 20 is a light source of the I / O display panel 10P in which a plurality of light emitting diodes (LEDs) that emit light of, for example, three primary colors are arranged. As will be described later, the backlight 20 performs an operation of turning on or off the LEDs of each color at high speed at a predetermined timing synchronized with the operation timing of the I / O display panel 10P under the control of the display drive circuit 1100.

  The display drive circuit 1100 is a circuit that drives the I / O display panel 10P (drives a line sequential operation) so that an image based on display data is displayed on the I / O display panel 10P.

The light receiving drive circuit 1200 is a circuit that picks up an object to be detected such as a fingertip and outputs the picked up images as a plurality of detected images so that light receiving data can be obtained in the I / O display panel 10P.
The display drive circuit 1100 drives the liquid crystal layer (light modulation layer) by performing pixel driving in a line sequential manner, whereas the light receiving drive circuit 1200 is a circuit for driving the optical sensor array in a line sequential manner. The light reception data from the optical sensor is accumulated in a frame memory (FM), for example, in units of frames, and is output to the image processing unit 1300 as captured images (a plurality of detected images).

  The image processing unit 1300 performs predetermined image processing (calculation processing) based on the captured image (detected image) output from the light receiving drive circuit 1200. Thereby, the image processing unit 1300 detects and acquires information (position coordinate data, data related to the shape and size of the object, etc.) related to an object that is in contact with or close to the I / O display panel 10P. In addition, since the distance (height) detection process in the z direction of the detection process has already been described with reference to FIGS. 4 to 6 in the first embodiment, the description thereof is omitted here.

  The application program execution unit 1400 is a circuit that executes processing according to predetermined application software based on the detection result by the image processing unit 1300.

Examples of the process corresponding to the application software include a process for increasing or decreasing the display button according to the height detection result, a process for changing the button itself, and the like.
In addition, the application of the present invention enables highly accurate height detection. For this reason, the height range is divided into several stages, and the application software has an amount of information that is more than binary information such as simple button switching, depending on which section the detected object such as a fingertip exists. Multi-value information can also be input. Therefore, the present invention can be applied to the operation of application software that controls the degree of operation, for example, the degree of action of a game or the like with the height of a fingertip.
In addition, in a simple example, the process of making the display data include the position coordinates (including the height) of an object to be detected such as a fingertip and displaying it on the I / O display panel 10P can be exemplified.

  Display data generated by the application program execution unit 1400, including button display and position data, is supplied to the display drive circuit 1100.

[Display panel overall configuration]
FIG. 8 is a diagram illustrating a configuration example of the I / O display panel 10P.
An I / O display panel 10P illustrated in FIG. 8 includes a display unit 10P1 including a display region DR and a sensor region SR, a display H driver (DH.DRV) 2200, and a display V driver (DV.DRV) 2300. In addition, the I / O display panel 10P includes a sensor readout H driver (SRH.DRV) 6SRH and a sensor readout V driver (SV.DRV) 6SRV.

  The display area DR and the sensor area SR are areas for modulating the light from the backlight 20 to emit display light and imaging an object that is in contact with or close to the display surface 11. For this purpose, in the display region DR and the sensor region SR, liquid crystal elements including a light modulation layer and light receiving elements (photosensors PS) are arranged in a matrix.

  The display H driver 2200 and the display V driver 2300 change the liquid crystal element of each pixel in the display unit 10P1 based on the display drive display signal and the control clock (CLK) supplied from the display drive circuit 1100 (FIG. 7). It is a circuit that drives line-sequentially.

  The sensor readout V driver 6SRV and the sensor readout H driver 6SRH are circuits that line-sequentially drive the light receiving elements (photosensors PS) of each pixel in the sensor area 2100 and acquire sensor output signals.

  The detection drive unit in the display device 10 according to the second embodiment includes the display drive circuit 1100 of FIG. 7 in addition to the sensor readout V driver 6SRV and the sensor readout H driver 6SRH that control imaging. Accordingly, the detection drive unit has a function of controlling the backlight 20 in synchronization with imaging.

[Pixel unit circuit configuration]
The pixel unit is a group of pixels that form the basis of a color arrangement such as three colors or four colors, and the display area DR and the sensor area SR are formed by regularly arranging the pixel units.

  FIG. 9 is an equivalent circuit diagram of the display pixel unit and the sensor unit included in the pixel unit. The sensor unit is usually arranged using a light shielding region provided between the display pixel units at the boundary of the pixel unit. Therefore, hereinafter, the arrangement region of the display pixel portion is referred to as “display region DR”, and the sensor portion is referred to as “light shielding region” or “sensor region”. The light shielding area and the sensor area are denoted by the same symbol “SR”. The display area DR and the sensor area (light-shielding area) SR are repeatedly arranged regularly on the display unit 10P1 in FIG.

  In the display region DR, an access transistor AT including a thin film transistor (TFT) is disposed in the vicinity of an intersection between the display scanning line DSCN extending in the horizontal direction and the display signal line DSL extending in the vertical direction. When the access transistor AT is composed of an FET, its gate is connected to the display scanning line DSCN, and its drain is connected to the display signal line DSL. The source of the access transistor AT is connected to the pixel electrode PE for each pixel. The pixel electrode PE is an electrode for driving the adjacent liquid crystal layer (light modulation layer) 37 and is usually formed of a transparent electrode material.

  A common electrode extending in a direction (horizontal direction) orthogonal to the display signal line DSL is provided with a counter electrode FE that faces the pixel electrode PE with the liquid crystal layer interposed therebetween. The counter electrode FE is usually provided between the pixels and is made of a transparent electrode material.

  In each pixel of the display region DR having such a configuration, the access transistor AT is turned on or off based on a display scanning signal supplied via the display scanning line DSCN. When the access transistor AT is turned on, a pixel voltage corresponding to the display signal supplied to the display signal line DSL at this time is applied to the pixel electrode PE, thereby setting a display state.

In the sensor region (light-shielding region) SR adjacent to the display region DR, a photosensor PS made of, for example, a photodiode is disposed, and the power supply voltage VDD is supplied to the cathode side for reverse bias. . A reset switch RSTSW and a capacitor C are connected to the anode side of the photosensor PS.
The storage capacity of the anode of the photosensor PS is determined by the size of the capacitor C, and the stored charge is discharged (reset) to the ground potential by the reset switch RSTSW. The time from when the reset switch RSTSW is turned off to when it is turned on corresponds to the charge accumulation time, that is, the imaging time.

In addition, a buffer amplifier BAMP and a readout switch RSW are connected in series between the anode of the optical sensor PS and the sensor line SL extending in the vertical direction.
The accumulated charge is supplied to the sensor line SL via the buffer amplifier BAMP at the timing when the readout switch RSW is turned on, and is output to the outside of the basic configuration 3100 of the pixel unit shown in FIG. The on / off operation of the reset switch RSTSW is controlled by a reset signal supplied by a reset line RSTL, and the on / off operation of the read switch RSW is controlled by a read control signal supplied by a read control line RCL. Is done. A sensor scanning signal line SSCN is constituted by the reset line RSTL and the read control line RCL.

FIG. 10 shows the connection relationship between the three pixels for displaying the three primary colors and the sensor readout H driver 6SRH.
In FIG. 10, a basic configuration 10PR of a pixel unit including a pixel (R pixel) at the time of red (R) display, a basic configuration 10PG of a pixel unit including a pixel (G pixel) at the time of green (G) display, and blue ( B) A pixel unit 10PB including pixels at the time of display (B pixel) is shown side by side in the display unit 10P1. Note that the color of the pixel is defined by the color arrangement of the color filter in other embodiments, but in this embodiment, it is defined by the color of the LED light source because of the field sequential method. Therefore, the basic configurations 10PR, 10PG, and 10PB of the three pixel units shown in FIG. 10 indicate the same pixel unit whose display color changes in time series.

Charges accumulated in a capacitor (not shown) or a parasitic capacitance connected to the photosensor PS in the basic configuration of each pixel unit are amplified by a buffer amplifier BAMP. The amplified charge is supplied to the sensor readout H driver 6SRH via the sensor line SL at the timing when the readout switch RSW is turned on.
A constant current source IG is connected to the sensor line SL, and a signal corresponding to the amount of received light is detected with high sensitivity by the sensor readout H driver 6SRH.

[Plane and cross-sectional structure of the pixel unit]
FIG. 11A shows a plane of the pixel unit (region division of the light-receiving anisotropy imparting unit 4 (see FIG. 1A)). FIG. 11B shows a cross section of the pixel unit corresponding to FIG.

In the (liquid crystal) display device 10 illustrated in FIG. 11B, a backlight 20 is arranged on the back surface (surface on the lowermost layer side) opposite to the display surface 11 (surface on the uppermost layer side in the drawing). ing.
(Liquid crystal) The display device 10 has two glass substrates bonded together, and various display layers 10P1 disposed between the backlight 20 and the display surface 11 between them and having various functional layers on the outer surface side. Has been. The display unit 10P1 here corresponds to the effective display area of the I / O display panel 10P of FIG.

  Although not shown in detail, the backlight 20 is a lighting device dedicated to an image display in which a light guide plate, a light source such as an LED, a light source driving unit, a reflection sheet, a prism sheet, and the like are integrally assembled.

The display unit 10P1 includes the TFT substrate 30 on the backlight 20 side and the counter substrate 31 on the display surface 11 side as the two glass substrates.
On the main surface of the TFT substrate 30 on the display surface 11 side, a light receiving layer 32 including an insulating film 32A, a wiring layer 32B, and a planarizing film 32C is formed. A first polarizing plate 40 is attached to the other main surface (back surface) of the TFT substrate 30.

A photodiode PD of the optical sensor PS is formed in the insulating film 32A in the light receiving layer 32. The upper surface (surface on the display surface 11 side) of the photodiode PD is a sensor light receiving surface.
In the wiring layer 32B having an opening above the photodiode PD, a large number of wirings such as the sensor line SL, the reset line RSTL, the read control line RCL, and the power supply line in FIG. 9 are formed.
The planarizing film 32C is formed so as to cover the wiring so as to planarize a step due to the wiring.

A display electrode layer 33 including a counter electrode FE (also referred to as a common electrode), an insulating film 33A, and a pixel electrode PE is formed on the light receiving layer 32 (on the display surface 11 side).
The counter electrode FE and the pixel electrode PE are made of a transparent electrode material, the counter electrode FE is arranged in a common size between pixels, and the pixel electrode PE is separated for each pixel. In particular, the pixel electrode PE has many slits that are long in the vertical direction.
A first alignment film 34 is formed to cover the surface of the pixel electrode PE and the underlying insulating film 33A.

  On one surface (back surface side) of the counter substrate 31, a color filter 35 as a light receiving anisotropy imparting portion, a planarizing film 35A, and a second alignment film 36 are formed.

The TFT substrate 30 is bonded to the counter substrate 31 so as to form an internal space via a spacer (not shown). At this time, the surface of the TFT substrate 30 on which the light receiving layer 32, the display electrode layer 33, and the first alignment film 34 are formed and the surface of the counter substrate 31 on which the color filter 35 and the second alignment film 36 are formed are opposed to each other. Both substrates are bonded together.
Liquid crystal is injected into the internal space between the two substrates from the portion where the spacer is not formed. Thereafter, when the liquid crystal injection portion is closed, the liquid crystal is sealed in the TFT substrate 30, the counter substrate 31, and the spacer, whereby the liquid crystal layer 37 is formed. Since the liquid crystal layer 37 is in contact with the first alignment film 34 and the second alignment film 36, the alignment direction of the liquid crystal molecules is determined by the rubbing direction of these alignment films.

For the liquid crystal layer 37 formed in this way, a pixel electrode PE for each pixel and a common electrode FE common to the pixels are disposed adjacent to each other in the layer thickness direction. These two types of electrodes are electrodes for applying a voltage to the liquid crystal layer 37. There are a case where two electrodes are arranged with the liquid crystal layer 37 interposed therebetween (vertical driving mode) and a case where two layers of two electrodes are arranged on the TFT substrate 30 side (horizontal driving mode). FIG. 11B shows the case of the latter lateral driving mode.
In this case, the pixel electrode PE and the counter electrode FE are insulated and separated, but the counter electrode FE on the lower layer side exerts an electrical action on the liquid crystal from between the pattern of the pixel electrode PE in contact with the liquid crystal layer 37 on the upper layer side. . Therefore, the direction of the electric field is the horizontal direction in the horizontal driving mode. On the other hand, when the two electrodes are arranged with the liquid crystal layer 37 sandwiched from the thickness direction, the direction of the electric field is the vertical direction (thickness direction).

  Regardless of the drive mode specification, the voltage can be driven in a matrix with respect to the liquid crystal layer 37 by the two electrodes. Therefore, the liquid crystal layer 37 functions as a functional layer (light modulation layer) that optically modulates the transmission. The liquid crystal layer 37 performs gradation display according to the magnitude of the applied voltage.

As another optical functional layer, a second polarizing plate 50 that forms a pair with the first polarizing plate 40 disposed between the backlight 20 and the TFT substrate 30 is attached to the surface of the counter substrate 31 on the display surface 11 side. It has been.
The display surface 11 side of the second polarizing plate 50 is covered with a protective layer (not shown), and the outermost surface is the display surface 11 for visually recognizing an image.

  In the second embodiment, the display area DR portion of the color filter 35 does not have color selectivity in connection with the adoption of the field sequential method. This is because the color is selected by the backlight 20 sequentially blinking the R, G, and B LEDs.

  On the other hand, in the sensor region (light shielding region) SR of the color filter 35, a light shielding unit 60 that also functions as a so-called black matrix is arranged, and two color filter units 61R and 61B are arranged on both sides in the horizontal direction. The color filter unit 61R is a red transmission filter that mainly transmits red (R) color components and cuts other color components. The color filter unit 61B is a blue transmission filter that mainly transmits the blue (B) color component and cuts other color components.

  With such a configuration of the color filter 35, the light coming from the front to the optical sensor PS by the action of the light shielding unit 60 does not enter the photodiode PD. On the other hand, light Lr is incident only from the right side of the photodiode PD because only the reflected light of red (R) is present when the backlight 20 emits R. Since only the blue (B) reflected light exists when the backlight 20 emits B light, the light Lb enters only from the left side of the photodiode PD.

FIG. 12 shows an arrangement plan view of the display area DR and the sensor area (light-shielding area) SR in the display unit 10P1. FIG. 13 is a perspective view showing a light path when a fingertip is brought close to the display surface having the area configuration shown in FIG.
As shown in FIG. 12, a sensor region (light-shielding region) SR is formed as a line extending in the column direction (vertical direction) of the display unit 10P1, and the display region DR is arranged therebetween. A square area indicated by a thick broken line in FIG. 12 is a pixel unit, and corresponds to a predetermined number of pixels. In the case of RGB three-color display, the pixel unit has an area corresponding to three pixels and a black matrix. However, in the field sequential method, the number of colors for color display and the number of pixels in the pixel unit do not necessarily correspond.

When the fingertip is brought close to the display surface of the display unit 10P1, the red component light Lr incident obliquely from the right direction passes through the color filter unit 61R and reaches the PD light receiving surface, but other color components in the same direction are Absorbed by the color filter unit 61R. Similarly, blue component light Lb incident obliquely from the left direction passes through the color filter unit 61B and reaches the PD light receiving surface, but other color components in the same direction are absorbed by the color filter unit 61B.
For example, a first detection image P1 (see FIGS. 4 to 6) is configured from a set of sensor outputs output from the photodiode PD when the red component light Lr is received. Further, for example, a second detection image P2 (see FIGS. 4 to 6) is configured from a set of sensor outputs output from the photodiode PD when the blue component light Lb is received.

[Operation of display device (including proximity measurement method for objects)]
Next, a procedure for acquiring the first detection image P1 and the second detection image P2 and an operation of the display device 10 including a height detection procedure will be described in detail.

  First, a basic operation of the display device 10, that is, an image display operation and an object imaging operation will be described. Since the configuration shown in FIG. 7 is assumed here, an example of how the height information after detection is used in the application software will be described.

In the display device 10 of FIG. 7, a display drive signal is generated in the display drive circuit 1200 based on display data supplied from the application program execution unit 1400. With this drive signal, line-sequential display drive is performed on the I / O display panel 10P, and an image is displayed.
At this time, the backlight 20 is also driven by the display drive circuit 1100, and is turned on and off in synchronization with the I / O display panel 10P.

  Here, with reference to FIG. 14, the relationship between the operation of turning on or off the backlight 20 and the display state of the I / O display panel 10P will be described.

First, for example, when an image is displayed with a frame period of 1/60 seconds, the backlight 20 is turned off (turned off) in the first half period (1/360 seconds) of each 1/3 frame period, and display is performed. I will not. On the other hand, in the second half period of each detection apparatus 1/3 frame period, the backlight 20 is turned on (turned on), a display signal is supplied to each pixel, and an image of that frame period is displayed. Yes.
Such a 1/3 frame period (1/120 seconds) is repeated three times for each of the colors R, G, and B, so that one frame of image is displayed.

  Thus, the first half period of each 1/3 frame period is a non-light period during which display light is not emitted from the I / O display panel 10P, while the second half period of each 1/3 frame period is an I / O display panel. It is a light period during which display light is emitted from 10P.

  Here, when there is an object (for example, a fingertip or the like) in contact with or close to the I / O display panel 10P, the light receiving element of each pixel in the I / O display panel 10P is driven by line-sequential light receiving drive by the light receiving drive circuit 1200. The object is imaged. As a result of imaging, a light reception signal from each light receiving element is supplied to the light receiving drive circuit 1200. In the light receiving drive circuit 1200, light receiving signals of pixels for one frame are accumulated and output to the image processing unit 1300 as captured images.

  The image processing unit 1300 performs predetermined image processing (arithmetic processing) described below based on the captured image, and information (position coordinate data, object shape) regarding an object that touches or approaches the I / O display panel 10P. And data related to size) are detected.

15A to 15B3 show more detailed timing charts.
FIG. 15A schematically shows a writing operation period and a scanning operation. FIG. 15B1 shows the R emission period, FIG. 15B2 shows the G emission period, and FIG. 15B3 shows the B emission period.
15B1 to 15B3 show that the non-light emitting period (backlight off) and the light emitting period (backlight on) are repeated in a short cycle (1/360 seconds), as in FIG. ing.

The first backlight off period T1 in one frame period is the R writing period, and the display scanning line DSCN (FIG. 9) is controlled by the display V driver 2300 (FIG. 8), so that the R display signal controls the access transistor AT. To the pixel electrode PE. When the backlight is turned on in the next period T2, R light emission display is performed.
This operation is repeated in the same manner for the G light emission display and the B light emission display by combining the periods T3 and T4 and the periods T5 and T6.

  In the present embodiment, the imaging operation by the optical sensor is performed in periods T2 and T6 corresponding to R light emission and B light emission among the periods T2, T4, and T6 corresponding to backlight on. In each period T2 or T4, a reset scan for scanning the reset line RSTL in FIG. 9 in a line sequence and a read scan in which the read control line RCL is scanned in a line sequence are delayed. The time for one screen of each scan is only half of the period T2 or T6, and the read scan is started at the same time as the scan for one screen of the reset scan is completed. The delay time between the reset scan and the read scan is a charge accumulation time (imaging time). When the charge accumulation (imaging) and discharge (read) operations are executed for one screen while having a fixed delay time, the sensor outputs from the plurality of sensor lines SL are time-sequentially and the sensor readout H driver of FIG. Read to 6SRH.

  A specific method for recognizing the first detection image P1 and the second detection image P2 performed by the sensor read-out H driver 6SRH and obtaining the height from the positional deviation is shown in FIGS. 4 and 6 in the first embodiment. I will omit it here.

FIG. 16 shows the analysis result of the imaging data. FIG. 16A1 and FIG. 16B1 are diagrams showing stereoscopic display and planar display of imaging data during R emission. FIGS. 16A2 and 16B2 are diagrams showing a stereoscopic display and a planar display of imaging data during R emission.
It can be seen that the position of the finger is located at the center of the imaging data, and the peak position of each imaging data is shifted to the left and right from the position where the finger is located. The peak position coordinates at the time of R emission are (x1, y1), and the peak position coordinates at the time of B emission are (x2, y1).

FIG. 17 is a graph in which the horizontal axis represents the finger height (detected object-light receiving surface distance), and the vertical axis represents the distance between peaks | x1-x2 | in the x direction.
The peak-to-peak distance | x1-x2 | increases monotonously with the finger height d. From this, when detection is used at a certain finger height, it is possible to determine whether or not the detected object is at a certain height by cutting the threshold between the peaks.

For example, when you want to detect with finger height d = 10 [mm]
“With finger” when peak-to-peak distance | x1-x2 |> 16,
“No finger” when peak-to-peak distance | x1-x2 | ≦ 16
Then, the presence or absence of the detection object can be determined in a non-contact manner.

  In addition, since the finger height d itself can be accurately obtained, the height information can be applied to various application software operations.

  The above-described detection of the finger height d, the presence / absence determination of the detected object using the finger height, and the position determination are performed by the image processing unit 1300 in FIG. Application program operation is applied to the application program execution unit 1400 based on the detection result from the image processing unit 1300, and the application result is fed back to display data as necessary.

In the present embodiment, the distance (height) from the sensor light receiving surface to the object to be detected can be accurately detected.
Further, the photosensor PS (the light receiving layer 32 in FIG. 11B) and the light receiving anisotropy imparting unit 4 (the color filter 35 in FIG. 11B) can be created by the same process as the display device 10. For this reason, the display device 10 according to the present embodiment does not require an external member required for the capacitance type or the like, and can reduce the cost.
Furthermore, by adopting the time division method, it is possible to obtain imaging data with very high resolution, and to calculate the distance from the light receiving surface to the detected object with high accuracy.

In the second embodiment, the following modifications are possible.
In the example shown in FIGS. 11 to 12, the structure directly shields the light receiving surface of the sensor. However, as shown in FIGS. 18B to 18C, the light shielding portion 60 is smaller than the sensor light receiving surface. Even if it becomes, it can employ | adopt, if the light reception anisotropy of optical sensor PS is maintained. Conversely, even if the light shielding portion 60 is made larger than the sensor light receiving surface, it can be adopted as long as the light receiving anisotropy of the optical sensor PS is maintained.

  Further, the light shielding portion that shields the sensor light receiving surface is not necessarily formed on the counter substrate 31 side. The light shielding portion may be formed on the TFT substrate 30 side. However, a separation for receiving oblique light is required between the sensor light receiving surface and the light shielding portion.

The detection light may be visible light or invisible light (ultraviolet light, infrared light). However, in the sense of a system that does not depend on a display image, it is desirable to employ invisible light as detection light. When the detection light is invisible light, an LED that emits invisible light that is lit at least during the imaging period needs to be added to the backlight 20, or another backlight including the LED needs to be provided.
Further, the liquid crystal mode may be TN, VA, IPS, FFS, ECB, or the like.

<3. Third Embodiment>
The present embodiment relates to a (liquid crystal) display device adopting a space division method, and is exemplified in FIGS.
Here, FIG. 19 corresponds to FIG. 11 related to the second embodiment, FIG. 20 corresponds to FIG. 12, and FIG. 21 corresponds to FIG. Hereinafter, FIG. 19 to FIG. 21 will be described differently from FIG. 11 to FIG. 13, and description of the configuration with the same reference numerals will be omitted. The basics of the detection method described in FIGS. 7 to 10 and the first embodiment are also applied to this embodiment.

FIG. 19 is a cross-sectional view and a plan view of two pixel units adjacent in the horizontal direction.
In the third embodiment, similarly to the second embodiment, the light receiving layer 32 and the display electrode layer 33 are formed on the TFT substrate 30 by the same process, and the color filter 15 is formed on the counter substrate 31. Photodiodes PD are arranged in an array on the light receiving layer 32, whereby the photosensor array 3 (see FIG. 1) is formed.

The space division method has two types of optical sensors PS.
The type of the optical sensor means that the light transmission characteristics of the color filter 15 are different. That is, since the light transmission characteristics of the color filter 15 are different, the photodiode PD has light receiving anisotropy. In this sense, the photosensor array is spatially separated.

Specifically, in the two optical sensors adjacent in the horizontal direction, both of the light receiving surfaces of the photodiodes PD are both shielded by the light shielding unit 60. However, the sensor region of one photosensor PS is an opening portion for a specific wavelength component such as an infrared light component IR on the right side of the light shielding portion 60, and conversely, the sensor region of the other photosensor PS is the light shielding portion 60. The left side of FIG. 6 has a structure of the color filter 15 that is an opening for a specific wavelength component.
The sensor area with the right opening is called a right anisotropic sensor area SRR, and the sensor area with the left opening is called a left anisotropic sensor area SRL.

Then, as shown in FIG. 20, pixel units (thick dashed square regions) each including the right anisotropy sensor region SRR and the left anisotropy sensor region SRL are arranged in a matrix in a checkered pattern as viewed from the display surface. Yes.
The arrangement method is not limited to the checkered pattern, but may be a stripe pattern.

In the second embodiment, when visible light is used as the detection light, there is no inconvenience that detection is impossible because there is no reflected light from the detected object when the display image is black.
Therefore, in the third embodiment, an infrared light IR (wavelength λ = 850 [nm]) infrared light IR is used as detection light, thereby adopting a system that does not depend on a display image. However, it is possible to build a similar system with visible light.

When the detection light is infrared light IR, a portion expressed as an opening of the right anisotropy sensor region SRR and the left anisotropy sensor region SRL needs to be an IR transmission portion 62 having IR selective transmission characteristics. There is.
There are various methods for forming the IR transmission part 62. Here, as shown in FIG. 19, the red (R) color filter part is overlapped with a red (R) transmission filter layer, and this is formed. Realized.

FIG. 22A shows a transmission spectrum of a filter (RB filter) having a two-layer structure of R and B.
Referring to the wavelength ranges of the respective colors shown in FIGS. 23A to 23C, the RB filter shown in FIG. 22A blocks visible light while favoring infrared rays (wavelength λ = 850 [nm]). It can be seen that it is transmitted. This makes it possible to build a system that does not depend on the display image.

The IR transmitting unit 62 may be a filter (RGB filter) having a three-layer structure of R, G, and B.
FIG. 22B shows the transmission spectrum.
It can be seen from this spectrum that the visible light blocking effect is higher than that of the RB filter, and the detection accuracy can be improved accordingly.

FIG. 24 shows imaging data of the right anisotropy sensor that receives the transmitted IR light in the right anisotropy sensor region SRR, and imaging data of the left anisotropy sensor that receives the transmitted IR light in the left anisotropy sensor region SRL. Indicates.
It can be seen that the position of the finger is located at the center of the imaging data, and the peak position of each imaging data is shifted to the left and right from the position where the finger is located. The peak position coordinates of the imaging data output from the right anisotropy sensor are (X1, Y1), and the peak position of the imaging data output from the left anisotropy sensor is (X2, Y1).
By calculating the x-coordinate difference | X1-X2 | of the peak position, a graph similar to FIG. 16 can be obtained.
When detection and use is performed at the same finger height as in the first and second embodiments, it is possible to determine whether or not an object to be detected exists at a certain height on the basis of the threshold value of the peak-to-peak distance. . Further, as in the second embodiment, position information including height information can be applied to the operation of application software.

In the third embodiment, it is preferable to perform display scanning and imaging scanning in one field in parallel without performing time-division LED blinking and control of the scanning operation in synchronization therewith. For this reason, the backlight 20 may be changed so that, for example, white LEDs and IR light LEDs are used as light sources, or the white light source and the IR light source may be separated by two backlights.
Further, as shown in FIG. 19, the pixel unit has a total area of three pixels and the sensor region in the case of RGB three-color mixing, and an area larger by one pixel in the case of four-color mixing.

In the third embodiment, as in the second embodiment, the height of the object to be detected can be accurately detected, and an external member required for a capacitance type or the like is unnecessary. Thus, it is possible to obtain a profit that the cost can be reduced.
Further, by adopting the space division method, it is not necessary to use a special three-color LED backlight, so that it can be realized at a low cost, and the display clock frequency of one screen can be lower than the time division.

In the third embodiment, the following modifications are possible.
In the example shown in FIGS. 19 to 21, the structure directly shields the light receiving surface of the sensor. For example, as shown in FIGS. 25B to 25D, the sensor light receiving surface is more completely covered. You may make it not cover a part or all. However, in these modified examples, the light receiving anisotropy of the optical sensor PS is maintained.

Further, similarly to the second embodiment, the light shielding portion that shields the sensor light receiving surface is not necessarily formed on the counter substrate 31 side. Further, the liquid crystal mode may be TN, VA, IPS, FFS, ECB, or the like.
In particular, in the case of the space division type, assuming that detection is performed with visible light, the present invention may be applied to a reflection type liquid crystal display device to image a shadow of an object to be detected. In that case, the backlight 20 including a special light source such as an IR light source becomes unnecessary.

<4. Fourth Embodiment>
[Reception anisotropy by lens array]
Next, the application of light reception anisotropy by the lens array will be described with reference to the drawings. The fourth embodiment is a kind of space division system, and shows a configuration that can be adopted instead of providing the IR transmitting unit 62 in the color filter 15 of the third embodiment.

  In the example of FIG. 26, for example, an array of cylindrical lenses is formed on the second polarizing plate 50. Since the cylindrical lens has a semi-cylindrical cross section, light incident obliquely from the right can be efficiently collected on the right sensor arranged on the left side. Similarly, light incident obliquely from the left can be efficiently collected on the left sensor arranged on the right side.

  In the fourth embodiment, a pair of photodiodes PD are arranged close to each other so as to receive left and right oblique light, thereby providing light receiving anisotropy. Therefore, in the present embodiment, the light receiving anisotropy is generated by the cooperation of the lens array as the light receiving anisotropy imparting unit 4 and the photo sensor array having the photodiode PD in a pair as the light sensor array 3. Yes.

  For example, an image obtained by the right sensor (PD) is set as the first detection image P1, and an image obtained by the left sensor (PD) is set as the second detection image P2, and height detection can be performed from the difference between the peak and the center of gravity.

  In the display device 10, it is desirable that the light receiving anisotropy imparting unit 4 is realized by a light-shielding filter or a color filter in terms of cost and thinning of the display device 10. In particular, the color filter is also provided in the display device 10 to which the present invention is not applied because of the color arrangement of the pixels. When the present invention is applied, the existing color filter is improved for imparting light receiving anisotropy. Just add. Therefore, when applying the present invention to the display device 10, it is most desirable to realize the light receiving anisotropy imparting unit 4 with a color filter from the viewpoint of cost reduction.

<5. Fifth embodiment>
The display device to which the present invention can be applied is not limited to display methods other than liquid crystal display, such as organic EL, inorganic EL, and electronic paper.

FIG. 27 shows a layout diagram when applied to an organic EL as an example.
The organic EL display device 70 includes an organic EL film that spontaneously emits R, G, and B light in the laminated structure of the substrate 71.
An organic laminated film 72IR having a light emission characteristic that emits or contains a large amount of infrared light component IR is formed on this organic EL film, and this is used as an IR light source.
In the present embodiment, it is possible to give the photodiode PD light reception anisotropy by the color filter 15 similar to that of the third embodiment.

  In addition, although it described by the space division system using infrared light IR here, there may not be IR light source and it is realizable also by a time division system.

<6. Sixth Embodiment>
The display device according to the present embodiment described above is input to various electronic devices shown in FIGS. 28 to 32, such as digital cameras, notebook personal computers, mobile terminal devices such as mobile phones, and video cameras. The video signal generated or the video signal generated in the electronic device can be applied to a display device of an electronic device in any field for displaying as an image or a video. Below, an example of the electronic device to which this embodiment is applied is demonstrated.

FIG. 28 is a perspective view showing a television to which the present invention is applied.
The television according to this application example includes a video display screen unit 110 including a front panel 120, a filter glass 130, and the like. As the video display screen unit 110, display devices according to the second to fifth embodiments can be used.

FIG. 29 is a perspective view showing a digital camera to which the present invention is applied, in which (A) is a perspective view seen from the front side, and (B) is a perspective view seen from the back side.
The digital camera according to this application example includes a flash light emitting unit 111, a display unit 112, a menu switch 113, a shutter button 114, and the like. As the display unit 112, the display devices according to the second to fifth embodiments can be used.

FIG. 30 is a perspective view showing a notebook personal computer to which the present invention is applied.
A notebook personal computer according to this application example includes a main body 121 including a keyboard 122 that is operated when characters and the like are input, a display unit 123 that displays an image, and the like. As the display unit 123, display devices according to the second to fifth embodiments can be used.

FIG. 31 is a perspective view showing a video camera to which the present invention is applied.
The video camera according to this application example includes a main body 131, a lens 132 for shooting an object on a side facing forward, a start / stop switch 133 at the time of shooting, a display unit 134, and the like. The display device according to this embodiment can be used as the display unit 134.

32A and 32B are diagrams showing a mobile terminal device to which the present invention is applied, for example, a mobile phone, in which FIG. 32A is a front view in an opened state, FIG. 32B is a side view thereof, and FIG. (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view.
The mobile phone according to this application example includes an upper casing 141, a lower casing 142, a connecting portion (here, a hinge portion) 143, a display 144, a sub-display 145, a picture light 146, a camera 147, and the like. As the display 144 and the sub-display 145, display devices according to the second to fifth embodiments can be used.

  DESCRIPTION OF SYMBOLS 1 ... Detection apparatus, 1R, etc .... Detection surface area | region, 3 ... Photosensor array, 4 ... Light reception anisotropy provision part, 6 ... Detection drive part, 10 ... Display apparatus, 10P ... I / O display panel, 11 ... Display Surface, 15 ... Color filter, 20 ... Back light, 37 ... Liquid crystal layer, 60 ... Shading part, 61R, 61B ... Color filter part, 62 ... IR transmission part, PS ... Optical sensor, PD ... Photodiode, SD ... Detected Object, P1 ... first detection image, P2 ... second detection image

Claims (16)

An optical sensor array having light receiving anisotropy;
A detection driver that drives the optical sensor array to image a detection object and generates a plurality of different detection images based on the light reception anisotropy;
The plurality of detection images are input, and an image portion corresponding to a shadow or reflection of the object to be detected included in the input detection images is based on the size of the positional deviation caused by the difference in the light receiving anisotropy. A height detection unit for detecting a distance (height) from the sensor light receiving surface of the photosensor array to the object to be detected;
A detection device having: The light-receiving anisotropy imparting section for imparting different light-receiving anisotropy within a set of a plurality of adjacent optical sensors of the photosensor array is provided on the side of the photosensor array where the object to be detected approaches. The detection device described. The optical sensor array has a plurality of light receiving anisotropies due to wavelength dependency of the amount of light received from different directions when receiving the transmitted light of the light receiving anisotropy applying unit. It is a two-dimensional arrangement of optical sensors,
The detection drive unit irradiates the detected object with a plurality of lights each having a different wavelength range in a time-sharing manner, and reflected light returned by the detected object returns the light receiving anisotropy imparting unit. A plurality of times of imaging with light in different wavelength ranges is performed by controlling each light receiving time when receiving by the plurality of light sensors after transmission in a time-sharing manner in synchronization with the irradiation of the plurality of lights. The detection device according to claim 2, wherein the plurality of detection images are generated by imaging of the image. The light-receiving anisotropy imparting unit includes a light-shielding unit, a portion facing the light-receiving surface of the one photosensor, and a pair of wavelength selection filter units that transmit different wavelength ranges on both sides in one direction of the light-shielding unit. The light receiving anisotropy is imparted to the photosensor by giving wavelength selectivity to light that enters obliquely from one side of the one direction and light that enters obliquely from the other side of the one direction. apparatus. The light-receiving anisotropy imparting unit has a pattern that shields a part or all of each sensor light-receiving surface on the side closer to the detected object with respect to the plurality of adjacent optical sensors. A light shielding filter in which at least one of the arrangement and the shape is different with respect to the plurality of optical sensors,
The photosensor array is defined by a plurality of photosensor arrays having different light receiving anisotropy depending on a degree of light shielding exerted by the pattern of the light shielding filter,
The detection device according to claim 2, wherein the detection driving unit drives the photosensor array to generate the plurality of detection images different from each other from the plurality of photosensor arrays. It further has a light irradiation part,
The light receiving anisotropy imparting unit is a lens array disposed on a light incident side of the photosensor array,
The lens array so that, when the light irradiating unit irradiates light having components in different directions, the optical sensors that mainly receive the reflected light reflected by the detection object according to the incident angle are different in the set. By arranging the plurality of photosensors for one lens, a plurality of photosensor arrays having different light receiving anisotropies are defined in the photosensor array,
The detection device according to claim 2, wherein the detection driving unit drives the photosensor array to generate the plurality of detection images different from each other from the plurality of photosensor arrays. The height detection unit identifies the image portion corresponding to the object to be detected in each of the plurality of detection images, and obtains the peak position of the received light amount of the identified image portion in each of the plurality of detection images. The detection device according to claim 1, wherein the height is obtained by calculation from a difference between peak positions of the received light amounts in the plurality of detection images. The height detection unit binarizes each sensor output included in the detection image for each of the plurality of detection images according to a magnitude relationship with a threshold value, and corresponds to the detected object from the obtained binarization information. The detection device according to claim 1, wherein an image part is identified, each centroid position of the image part is calculated, and the height is obtained by calculation from a difference between the obtained centroid positions. A light modulation unit that modulates incident light according to an input video signal and outputs a generated display image;
A display surface for displaying the display image from the light modulator;
An optical sensor array having light receiving anisotropy;
A detection drive unit that drives the photosensor array to image a detection object in contact with or close to the display surface and generates a plurality of different detection images based on the light reception anisotropy;
The plurality of detection images are input, and an image portion corresponding to a shadow or reflection of the object to be detected included in the input detection images is based on the size of the positional deviation caused by the difference in the light receiving anisotropy. A height detection unit for detecting a distance (height) from the sensor light receiving surface of the photosensor array to the object to be detected;
A display device. The display device according to claim 9, wherein the detection driving unit generates the plurality of detection images by imaging the detection target object during a period in which the light modulation unit does not output the display image. The detection drive unit generates the plurality of detection images by imaging the detection object by irradiating the detection object with invisible light different from visible light modulated by the light modulation unit. The display device described. The light modulation unit is disposed between the photosensor array and the display surface,
Between the light modulation unit and the display surface, a color filter that restricts a wavelength range of transmitted light is disposed for each portion of the light modulation unit facing the optical sensor,
The light-shielding portion of the color filter is disposed opposite to the light-receiving surface of the photosensor, and the wavelength range of transmitted light of the color filter portion adjacent to the light-shielding portion is at least one direction within the sensor placement surface with respect to each photosensor The display device according to claim 9, wherein the photosensor array has the light receiving anisotropy by being different. The detection driving unit irradiates the detected object with a plurality of lights each having a different wavelength range in a time-sharing manner, and the reflected light reflected and returned to the detected object passes through the color filter. By performing time-sharing control of each light receiving time when receiving light by a plurality of optical sensors in synchronization with the irradiation of the plurality of lights, imaging is performed a plurality of times with light in different wavelength ranges, and the imaging is performed by the plurality of imaging operations. The display device according to claim 11, wherein a plurality of detected images are generated. Imaging a detection object by driving a photosensor array having light reception anisotropy, and generating a plurality of different detection images based on the light reception anisotropy;
The plurality of detection images are input, and an image portion corresponding to a shadow or reflection of the object to be detected included in the input detection images is based on the size of the positional deviation caused by the difference in the light receiving anisotropy. Measuring the distance (height) from the sensor light receiving surface of the photosensor array to the object to be detected;
Measuring method of proximity distance of objects including Imaging a detected object a plurality of times with a combination of photosensors corresponding to different photodetection anisotropy from a plurality of photosensors in the photosensor array having photodetection anisotropy;
A position generated by the difference in the light receiving anisotropy in the image portion corresponding to the shadow or reflection of the object to be detected included in the plurality of input detection images by inputting the plurality of detection images obtained by the plurality of times of imaging. Measuring the distance (height) from the sensor light receiving surface of the photosensor array to the detected object based on the magnitude of the deviation;
Measuring method of proximity distance of objects including Each of the plurality of photosensors in the photosensor array is a photosensor having the light reception anisotropy by giving wavelength dependency to the amount of light received from different directions.
In the step of imaging the detected object, the detected object is irradiated with a plurality of lights each having a different wavelength range in a time-sharing manner, and light in the corresponding wavelength range is irradiated to the detected object. The light receiving time of the plurality of light sensors is controlled in a time-sharing manner in synchronization with the irradiation of the plurality of lights so that the light sensor of the light receiving sensitivity peak corresponding to the reflected light that is reflected back can be received. 15. A method for measuring a proximity distance of an object according to 15.

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